Vapor-electric-lamp manufacture.



PATENTBD MAY 24, 1904.

P. G. HEWITT. VAPOR ELECTRIC LAMP MANUFACTURE.

APPLIOATION FILED D130. 4. 1903.

N0 MODEL.

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UNITED STATES Patented May 24, 1904.

PATENT OFFICE.

PETER COOPER HEWITT, OF NEW YORK, N. Y., ASSIGNOR TO COOPER HEWITT ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

VAPOR-ELECTRlC-LAMP MANUFACTURE.

SPECIFICATION forming part of Letters Patent No. 760,789, dated May '24, 1904.

Application filed December 4, 1903. Serial No- 183,708. (No model.)

To all whom it may concern.-

Be it known that I, PETER COOPER HEWITT, a citizen of the United States, and a resident of New York, county of New York, State of New York, have invented certain new and useful Improvements in Vapor-Electric-Lamp Manufacture, of which the following is a specification.

In manufacturing gas or vapor electric apparatus wherein one of the electrodes is of iron or other material in solid form it is customary to drive off the occluded gases from the solid electrode by heating the electrode by an electric current. This process is set forth in United States Patent No. 682,692, issued to Peter Cooper Hewitt on the 17th day of September, 1901. In the patent referred to it is stated to be of advantage to heat the lamp-terminal from which it is desired to expel the occluded gases by making the said terminal for the time being the cathode of the apparatus. The cathode is thereby readily heated to a Very high temperature and the occluded gases and impurities are driven ofi. Owing to the tendency which appears in the operation of apparatus of this class causing the current to seek the most remote part of the cathode, there is present under ordinary circumstances the danger that the lead-wire connected with the temporary cathode may be attacked by the current and its seal may become injured. In any case the connections at the seal are liable to become unduly heated unless measures are taken to prevent such an occurrence.

The present invention relates to means for protecting the seal of an apparatus of the class described during the process of manufacture.

The invention consists in surrounding the seal or the lead-wire where it passes into the container with a portion of the conducting liquid which is to form the permanent cath ode or negative electrode of the apparatus. In the mercury-vapor apparatus, for example, I place around the seal behind the solid electrode a small quantity of mercury, which may afterward be poured over into the main body of the negative electrode prior to putting the apparatus intoactual use. This is found to be a sufficient protection to the seal, inasmuch as any current which might seek to pass into the most remote end of the temporary cathode would enter the mercury and cause no damage to the platinum lead, while the injurious effects of heat as such upon the lead-wire or seal are prevented by reason of the heat-absorbing and heat-disposing qualities of the mass of mercury.

I have illustrated my invention in a very simple form in the accompanying drawing, which is a vertical section of a U-shaped mercury-vapor lamp.

In the drawing, 1 is a container, of glass or other transparent material.

2 is the permanent negative electrode, of mercury, located at one end of the container, and 8 is the permanent positive electrode, which may be of iron and is located at the opposite extremity of the container.

At 4 is shown the seal off, which during the manufacture of the apparatus is connected with a suitable pump for exhausting the air and withdrawing the occluded gases and other impurities. In order to expel from the solid electrode 3 such occluded gases and impurities, the same is heated in the manner described in the Hewitt patent above referred toby means, for example, of an intermittent current of high potential applied to both terminals of the apparatus. During this process the electrode 3 is made the cathode and a high degree of heat is developed at the electrode, thereby expelling the gases and impurities. At the same time the pump is generally kept in operation and the expelled gases and impurities are drawn out from the container.

To connect the positive lead-wire, which is shown at 5, and the seal between the same and the glass of the container, I place a small amount of mercury (shown at 6) around the wire and its seal, whereby the wire and the seal are protected from injury, as described above.

I claim as my invention 1. As a means for protecting the seal and the lead-wire to the positive electrode in avapor electric apparatus having a negative electrode of mercury and'a positive electrode of solid material, a mass or puddle of mercury located around the seal during the process of manufacture.

2. In a vapor electric apparatus having a negative electrode of conducting liquid and a positive electrode of solid conducting material, in the manufacture of which apparatus the electrodes are heated to drive ofi' occluded gases and other impurities, means for protecting the seal and the lead-wire to the positive electrode consisting of a mass of the same material as the negative electrode surrounding the seal during the process of manufacture.

3. The combination with a vapor electric apparatus having a negative electrode of con- PETER COOPER HEWITT.

Witnesses:

l/VM. H. CAPEL, GEORGE H. STOGKBRIDGE. 

